Absorbent swabs are generally known in the medical arts for use in collecting fluid specimens from a patient for further analysis. Medical swabs commonly comprise a fibrous swab tip at one end of an elongated stick or shaft which is manually handled to contact the swab tip with a selected part of a patient, for example the surface of a wound. As a result, some tissue fluid, including cellular matter, adheres to the swab tip which can then be contacted with one or more selected reagents to indicate the presence of infection or other information regarding patient condition. Tests commonly performed with swab specimens include fluorescent tests, enzymatic tests, monocolonal antibody based tests and agglutination tests.
Still greater diagnostic accuracy can sometimes be achieved by analysis of a biopsy sample. Typically, the biopsy sample may be taken by means of a cylindrical, sharpened biopsy punch located at one end of an elongated stick or shaft which is manually punched into the tissue of interest. The punch sample is then homogenized and analysed with suitable reagents to arrive at a diagnosis.
In accordance with standard techniques, the collected biological specimen (swab or biopsy) is normally transferred from the swab tip or the biopsy punch to a slide or other laboratory apparatus such as a test tube or the like for contact with selected reagents and further analysis. However, it can be difficult to ensure transfer of a sufficient specimen quantity from the swab tip to the laboratory slide or test tube to ensure accurate test results. Contamination of the sample can accidentally take place during the transfer, and delays between the time of specimen collection and actual test performance can also result in a decrease in test reliability. The need for a separate analysis step also increases the overall cost of the diagnostic procedure.
U.S. Pat. No. 5,266,266 describes a diagnostic swab having a hollow swab shaft extending between a swab tip adapted to collect a targeted specimen and a break-off nib that protrudes into a reservoir of reagent solution. Following collection of a sample on the swab tip, deformation of the reservoir is effected to sever the nib from the swab to open the rear end of the swab shaft and permit reagent flow from the reagent chamber through the swab shaft to the swab tip. The swab is fully enclosed in a housing having a cap, in which may be provided a further reagent, such as treated beads, for reaction with the eluate from the swab tip. This swab arrangement requires quite large amounts of thermoplastic molding material for its construction, and quite large amounts of reagent solution for satisfactory operation, with resulting increased cost and loss of sensitivity due to dilution of the swab sample.
U.S. Pat. No. 6,248,294 describes a self-contained diagnostic swab arrangement comprising a conventional swab and a diagnostic housing to receive and enclose the swab after collection of a sample. The diagnostic housing includes a reservoir of reagent liquid, and a diagnostic test strip extending up one side of the housing. This diagnostic swab arrangement requires quite large amounts of thermoplastic molding material for its construction, and an excessive amount of reagent solution for satisfactory operation.